Developmental Disabilities in Early and Middle Childhood

Original Editor - Jess Bell based on the course by Tracy Prowse
Top Contributors - Jess Bell, Kim Jackson, Wanda van Niekerk, Naomi O'Reilly, Tarina van der Stockt, Rucha Gadgil and Cindy John-Chu

This article or area is currently under construction and may only be partially complete. Please come back soon to see the finished work! (9/08/2021)

Introduction

"Developmental disabilities are a diverse group of severe chronic conditions that are due to mental and/or physical impairments. People with developmental disabilities have problems with major life activities such as language, mobility, learning, self-help, and independent living."

Developmental disabilities (DDs) includes conditions such as:

• Attention deficit hyperactivity disorder (ADHD)
• Autism
• Intellectual disability
• Learning difficulties (including ADHD, developmental coordination disorder (DCD) / dyspraxia, auditory processing disorder)
• Blindness
• Cerebral palsy
• Moderate to profound hearing loss
• Seizures
• Stuttering / stammering
• Other developmental delay

The prevalence of DDs is increasing. From 1997 to 2008 autism prevalence increased by 289.5 percent and ADHD increased by 33 percent. The 2009-2017 National Health Interview Survey showed a 9.5 percent increase in the prevalence of DDs in children aged 3 to 17 years.

Movement Difficulties

Hypermobility

Muscle Tone

Muscle tone is defined as: “the tension in the relaxed muscle” - GANGULY i.e.

the amount of tension or resistance to stretch in a muscle. WEB

Hypotonia

Hypotonia is defined as: “poor muscle tone resulting in floppiness. It is abnormally decreased resistance encountered with passive movement of the joint.” MADHOK

There are different causes of hypotonia: WEB

• Lower motor neuron disease (neurological, metabolic and genetic causes)
• Infections (meningitis, polio)
• Genetic (Down’s syndrome,  Prader-Willi, Tay-Sachs, spinal muscular atrophy, Charcot-Marie-Tooth syndrome, Marfan syndrome and Ehlers-Danlos syndrome)
• Metabolic (rickets)
• Congenital hypothyroidism
• Genetic acquired (muscular dystrophy)
• Benign congenital hypotonia (BCH)
  • NB: BCH is a symptom, rather than a diagnosis. Diagnosis is made in the absence of other diagnoses (such as joint hypermobility, aspergers, autism, DCD).
• Low connective tissue tone - this is considered better terminology to describe hypermobility or increased laxity in connective tissue
• Joint hypermobility
  • This term is used when only the connective tissue in the joints is affected
• Benign Joint Hypermobility Syndrome (BJHS)

Benign Joint Hypermobility Syndrome

BJHS is a hereditary condition that causes musculoskeletal symptoms in hypermobile patients, without other rheumatological features being present. It appears to be caused by an abnormality in collagen or the ratio of collagen subtypes.

Figure 1. Beighton score.

Diagnosis is made based on a medical examination and use of the Beighton score (see Figure 1)

Children with BJHS are susceptible to joint injury or dislocation, reduced stability, and a decreased ability to build muscle strength. They may tire easily, complain of pain or digestive issues, but symptoms are variable. They tend to be exacerbated during growth spurts, adolescence and hormone changes.

The Good News

• Strengthening is beneficial
• Swimming, pilates, climbing, horse riding can help (i.e. non-impact activities):
  • If children engage in high impact sports, they may require rest days (particularly if they are complaining of night pain after activity)
• Specific movement programmes such as Physifun are beneficial

NB: If  BJHS children participate in ballet, gym or dancing, it is important that they avoid “locking out” their joints. Instead, teach them to have “soft knees”. Also watch for lordotic postures and tight hamstrings.